Process for preparing polymer bound UV stabilizers

ABSTRACT

Ultraviolet light stabilizers are chemically bound to anhydride containing polymers or copolymers. Polymeric stabilizers are prepared by the reaction of primary amino or hydrazido-substituted UV absorbers with some or all of the anhydride groups of the polymer or copolymer to form pendant stabilizer substituted imide or amic acid groups. The polymer bound stabilizers are not lost from the polymer system by volatilization, migration, or extraction, even at high temperature. The polymeric stabilizers of this invention may be used as they are or as concentrates to stabilize other polymer systems.

This is a division of copending application Ser. No. 370,376 now U.S.Pat. No. 4,981,914, filed June 23, 1989, which is a division ofapplication Ser. No. 84,608, filed Aug. 12, 1987, now U.S. Pat. No.4,868,246, issued Sept. 19, 1989.

BACKGROUND OF THE INVENTION

This invention relates to polymer bound UV stabilizers. This inventionalso relates to the use of these polymer bound UV stabilizers tostabilize polymers or polymer blends against photochemical degradation.

When exposed to sunlight or to strong fluorescent illumination, mostplastics undergo degradation. This usually results in color developmentand loss of physical properties. To overcome these problems, polymersare normally protected against photochemical attack by the incorporationof ultraviolet light stabilizers. UV stabilizers initially perform wellin plastic compositions; however, they tend to be removed over a periodof time by vaporization, migration or degradation under the action ofelevated temperatures, or by the action of various solvents and cleaningagents, etc. The plastic compositions then degrade, discolor and in manyinstances become so brittle they can be easily broken.

Three factors affect the performance of the stabilizer in a polymercomposition: the intrinsic activity of the stabilizer functional groupon a molar basis, the compatibility or solubility of the stabilizer inthe polymer system, and the ability of the stabilizer to remain in thepolymer system. The third factor is often the dominant factor (G. Scott,New Developments in Rubber-Bound Antioxidants. Rubbercon 77, Int. RubberConf., 1977, 1, paper #19). Consequently, there has been considerableeffort toward the development of stabilizers that are less volatile,more compatible and less readily lost during fabrication and exposure tothe environment. Engineering thermoplastics are processed at hightemperatures. A considerable amount of the additive may be lost when thehot polymers are exposed to the atmosphere or a vacuum (ventedextruders) unless the additive has a very low vapor pressure. It isessential to use high molecular weight stabilizers that are not lostthrough drying, extrusion, and molding steps. Low volatility is alsorequired for applications such as automotive paints where the stabilizermust suffer only minimal loss during oven drying and outdoor exposure(Kirk-Othmer Encyclopedia of Chemical Technology, third Edition, Vol 23,p 619, John Wiley & Sons, New York, N.Y.). For polymers that come incontact with foodstuffs it is essential that the stabilizers benon-toxic or non-extractable from the polymer into the foodstuff. Manyof the commercial low molecular weight UV stabilizers are too volatileto be used in these applications. Obviously, polymer bound stabilizersare preferred where FDA approval is required in the end-use.

Various approaches have been used to overcome volatility andcompatibility shortcomings. One solution to the volatility and migrationproblems of UV stabilizers has been to prepare stabilizers withpolymerizable groups. The choice then becomes to either polymerize themonomeric stabilizers to form homopolymers for use as additives,copolymerize the stabilizer with another monomer for use as an additive,or incorporate the stabilizer monomer in the preparation of the hostpolymer. In the homopolymer approach the monomers are often difficult toprepare and the homopolymers are usually incompatible with the polymersto be stabilized (J. Fertig, A. I. Goldberg and M. Shoultchi, J. Appl.Polym. Sci., 10, pp 663 (1966)).

For addition polymers and copolymers, the more popular approach is tocopolymerize the polymerizable stabilizer with another monomer, therebyforming either a masterbatch for use as an additive, or simply a polymeror copolymer with sufficient stabilizer attached to the backbone of the(co)polymer chain. (D. Bailey, O. Vogl, J. Macromol. Sci.--Rev.Macromol, Chem., C 14(2), pp 267-93 (1976)).

U.S. Pat. No. 4,042,773 demonstrates the attachment of UV absorbers topolymers and copolymers by first attaching the stabilizer onto theinitiator used in the preparation of the polymer or copolymer to bestabilized.

Condensation polymers and copolymers have had stabilizer groupsincorporated into the polymer backbones by reacting suitablyfunctionalized UV stabilizers with reactive condensation monomers (U.S.Pat. Nos. 3,385,910, 3,391,110, 4,354,016, 3,862,087 and 3,213,058).

Monomeric stabilizers have been grafted onto polymeric backbones by meltprocessing in a Brabender Plasticizer. However, the extent of thegrafting was quite low and most of the ungrafted stabilizer could bereadily extracted out of the polymer blend (Y. N. Sharma, M. K. Naqvi,P. S. Gawande, I. S. Bhardwaj, J. Appl. Polym. Sci., 27, pp 2605-13(1983)).

It is also known in the art to endcap polymers with reactive UVstabilizers (East German Patents 208,470 (CA101:193120z) and 208,471(CA101:193114a)).

Another method of preparing polymer bound stabilizers is to attachstabilizer groups to existing polymers or copolymers. UV stabilizerscontaining thiol groups have been attached to rubber modifiedthermoplastics such as ABS or other rubber lattices using peroxideinitiators (G. Scott, M. Ghaemy, Polym. Deg. and Stab., 3(1980-81),253-263). European Patent Application 84,882 (CA99:141092n) discloses amethod of attaching thiol UV stabilizers to rubber modifiedthermoplastics in the presence of a peroxide initiator in a meltprocessing step. U.S. Pat. No. 2,849,373 discloses the formation of anionically bonded benzophenone stabilizer by reacting a polymer withpendant dimethylamino groups with2-carboxy-2'-hydroxy-4'-methoxybenzophenone thereby producing a salt,with the UV stabilizer ionically bound to the polymer.

Considerable activity has involved modification of copolymers containingreactive functionalities with stabilizers containing groups that reactwith the reactive functionality of the copolymer. Two examples of thistechnique are the modification of glycidyl (meth)acrylate copolymers andthe modification of maleic anhydride copolymers. Japanese Patent71/26,860 (CA77: 20857c) covers the attachment of UV stabilizerscontaining amino groups, hydroxyl groups or isocyanate groups tocrosslinked glycidyl methacrylate-divinylbenzene copolymers orcrosslinked styrene-maleic anhydride-divinylbenzene copolymers. Theattachment is through the respective polymer's reactive epoxide oranhydride groups. A particularly attractive approach to nonmigrating UVabsorbers is demonstrated by the reaction of2-hydroxy-4-(2-hydroxyethoxy)benzophenone with maleic anhydride graftedpolyethylene to form a polymer bound 2-hydroxybenzophenone semi-ester(Japanese Patent 85/84,378, CA103: 161319w).

SUMMARY OF THE INVENTION

The present invention is directed to a polymer with recurring unitsselected from ##STR1## or both in which the units occur either in thepolymer backbone, on grafted side chains, as pendant units, or ascombinations thereof and wherein x is 0 or 1.

R¹ and R² are independently selected from hydrogen, alkyl of 1 to 6carbons, cycloalkyl of 5 to 7 carbons, phenyl, chlorine, or bromine.##STR2## is the residue of a primary amino or hydrazido substitutedstabilizer group selected from (a) 2-hydroxybenzophenones, (b)2-(2-hydroxyphenyl)-2H-benzotriazoles, (c) aryl salicylates, or (d)oxalic acid amides.

DETAILED DESCRIPTION OF THE INVENTION

In accordance with the invention, polymers containing pendant UVstabilizer groups are prepared from:

a) cyclic anhydride containing polymers or copolymers and reactive UVstabilizer groups with primary amino or hydrazido functionality; or

b) the copolymerization of ethylenic or vinyl aromatic monomers withN-substituted imides (or N-substituted amic acids) of cyclic alpha,beta-unsaturated dicarboxylic acid anhydrides where the N-substituentscontain UV stabilizing groups.

Preferably, the cyclic anhydride containing polymer or copolymer is acopolymer of maleic anhydride. The polymer bound UV stabilizer groupsare attached as pendant N-substituents on the amide group of the polymeror as N-substituents of intermediate amic acids which are capable ofcyclizing to the amide group upon heating above 200° C. The compositionsare useful as thermal and light stabilizers for polyolefins, (rubbermodified) styrenics and engineering thermoplastics such aspoly(phenylene oxide), poly(phenylene ether), polycarbonate and polyblends of these materials.

The ultraviolet light absorbing stabilizer groups (G) of this inventionare as follows:

(a) 2-hydroxybenzophenones ##STR3## wherein: R³ and R⁴ are independentlyselected from hydrogen, hydroxyl, alkyl of 1 to 8 carbons, alkoxyl of 1to 4 carbons or a connecting group X¹ with the proviso that only one ofeither R³ or R⁴ can be connecting group X¹. X¹ is a direct bond or adivalent radical selected from --NH--C(═O)--(CH₂)_(b) --O--, --CH₂ --CH₂--O--, --NH--C(═O)--, --NH--S(═O)₂ --, --R⁵ --NH--C(═O)--, or --R⁵--NH--S(═O)₂ --, in which R⁵ is alkylene of 2 to 12 carbons. b is 0, 1,or 2. Additional substituents for the aromatic nuclei include hydroxyl,alkyl of 1 to 8 carbons, and alkoxy of 1 to 4 carbons.

Preferably, R³ is hydrogen, hydroxyl or alkoxy of 1 to 4 carbons, R⁴ isthe connecting group X¹, X¹ is --NH--C(═O)--(CH₂)_(b) --O-- or --CH₂--CH₂ --O--, and b is 1 or 2. Most preferably, R³ is hydrogen or alkoxyof 1 to 4 carbons, R⁴ is X¹ and X¹ is --NH--C(═O)--(CH₂)_(b) --O--, andb is 1.

(b) 2-(2-hydroxyphenyl)-2H-benzotriazoles ##STR4## wherein: R⁶ may behydrogen, alkyl of 1 to 4 carbons, alkoxy of 1 to 4 carbons, carboxyl,alkoxycarbonyl of 2 to 11 carbons, carboxylic acid amide, chlorine,bromine, sulfonic acid, alkylsulfonyl, or the connecting group X². R⁷may be hydrogen, alkyl of 1 to 8 carbons, aralkyl of 7 to 12 carbons,aryl of 6 to 14 carbons or the connecting group X³.

X² is a divalent radical selected from --NH--C(═O)-- and --NH--S(═O)₂ --

X³ is a direct bond or a divalent radical selected from--NH--C(═O)--(CH₂)_(b) --C(═O)--NH--(CH₂)_(y), --NH--C(═O)--(CH₂)_(b)--NH--(CH₂)_(y) --, --NH--C(═O)--(CH₂)₂ --, --(CH₂)_(y) --,--NH--C(═O)--(CH₂)_(z) --S--CH₂ --C(═O)--NH--(CH₂)_(y) --,--NH--C(═O)--(CH₂)_(b) --O--, --NH--C(═O)--, and --CH₂ CH₂ O--

in which b is as previously defined, y is 1, 2, or 3, and z is 1 or 2.

Additional substituents for rings A and B include alkyl of 1-4 carbons,alkoxy of 1-4 carbons and halogen (Cl, Br). The substitution must besuch that one and only one of the substituents (R⁶ and R⁷) is theconnecting group.

Preferably, R⁶ is hydrogen or chlorine, R⁷ is X³, X³ is--NH--C(═O)--(CH₂)_(b) --O--, --NH--C(═O)--(CH₂)_(z) --S--CH₂--C(═O)--NH--(CH₂)_(y) --, --(CH₂)_(y) --, --CH₂ CH₂ O--, ##STR5## or--NH--C(═O)--(CH₂)_(z) --, y is 1 or 2, b is 1 or 2, and z is 1 or 2.

Most preferably, R⁶ is hydrogen, R⁷ is X³, X³ is --(CH₂)_(y) --,##STR6## --NH--C(═O)--(CH₂)_(b) --O-- or --NH--C(═O)--(CH₂)_(z), y is 1,z is 2 and b is 1.

(c) Aryl salicylate derivatives ##STR7## wherein: R⁸ is substituted orunsubstituted aryl of 6 to 10 carbon atoms.

X⁴ is a direct bond or diradical selected from: ##STR8## in which b andz are as previously defined.

Z is selected from --NH--, --S--, or --O--.

Preferably, R⁸ is unsubstituted or substituted aryl of 6 to 8 carbons,and X⁴ is --NH--C(═O)--(CH₂)_(b) --C(═O)--NH--. Most preferably, R⁸ isphenyl and X⁴ is --NH--C(═O)--(CH₂)_(b) --C(═O)--NH-- wherein b is O.

(d) Oxalic acid amide derivatives of the structure ##STR9## wherein: R⁹is selected from hydrogen, hydroxyl, alkoxy, or alkylthio of 1 to 12carbons, acyloxy or acylthio of 2 to 12 carbons, alkyl of 1 to 8carbons, aryl of 6 to 12 carbons, chlorine or bromine.

R¹⁰, R¹¹, R¹², and R¹³ are independently selected from hydrogen, alkylof 1 to 8 carbons, aryl of 6-12 carbons, aralkyl of 7 to 13 carbons,alkoxy or alkylthio of 1 to 12 carbons, chlorine, bromine, oralkoxycarbonyl of 2 to 8 carbons.

X⁵ is a direct bond, alkylene of 2 to 12 carbons, aralkylene of 7 to 13carbons, or alkenylene of 3 to 12 carbons.

Preferably, R⁹ is hydroxyl or alkoxy of 1 to 4 carbons, R¹⁰, R¹¹, R¹²,and R¹³ are independently selected from hydrogen or alkyl of 1 to 4carbons, and X⁵ is a direct bond. Most preferably, R⁹ is ethoxy, R¹¹,R¹², R¹³, and R¹⁴ are hydrogen and X⁵ is a direct bond.

Examples of the 2-hydroxybenzophenones which may be reacted with theanhydride polymers or copolymers include the following:

(4-benzoyl-3-hydroxyphenoxy)acetylhydrazide,

4-amino-2-hydroxybenzophenone,

2-hydroxy-4-(2-aminoethoxy)benzophenone,

(4-(2-hydroxybenzoyl)-3-hydroxyphenoxy)acetylhydrazide,

(4-(4-methoxybenzoyl)-3-hydroxyphenoxy)acetylhydrazide,

4-(4-benzoyl-3-hydroxyphenoxy)butenoic acid hydrazide,

2-(2',4'-dihydroxybenzoyl)benzoic hydrazide, and

2-(2'-hydroxy-4'-methoxybenzoyl)benzoic hydrazide.

Examples of the 2-(2-hydroxyphenyl)-2H-benzotriazoles include thefollowing:

3-(3-(2H-benzotriazol-2-yl)-4-hydroxy-5-t-butylphenyl)propionhydrazide,

3-(3-(5-chloro-2H-benzotriazol-2-yl)-4-hydroxy-5-t-butylphenyl)propionhydrazide,

3-(3-(2H-benzotriazol-2-yl)-4-hydroxy-5-methylphenyl)propionhydrazide,

3-(3-(2H-benzotriazol-2-yl)-2,6-dihydroxyphenyl)propionhydrazide,

3(3-(5-chloro-2H-benzotriazol-2-yl)-4-hydroxy-5-methylphenyl)propionhydrazide,

2-(4-amino-2-hydroxyphenyl)-2H-benzotriazole,

2-(4-amino-2-hydroxyphenyl)-5-hydroxy-2H-benzotriazole,

2-(4-amino-2-hydroxyphenyl)-5-chloro-2H-benzotriazole,

2-[2-hydroxy-5-(aminomethyl)phenyl]-2H-benzotriazole,

2-[2-hydroxy-3-(aminomethyl)-5-methylphenyl]-2H-benzotriazole,

(4-(2H-benzotriazol-2-yl)-3-hydroxyphenoxy)acetyl hydrazide,

(4-(5-methoxy-2H-benzotriazol-2-yl)-3-hydroxyphenoxy)acetyl hydrazide,

(4-(5-chloro-2H-benzotriazol-2-yl)-3-hydroxyphenoxyacetyl hydrazide, and

3-(2H-benzotriazol-2-yl)-4-hydroxybenzoic acid hydrazide.

Examples of the salicyclic acid derivatives include the following:

phenyl 4-aminosalicylate and

N-(3-hydroxy-4-(phenoxycarbonyl)phenyl)-N'-aminooxamide.

Examples of oxamides include the following:

N-(2,4,6-trichlorophenyl)-N'-aminooxamide,

N-(2,4,6-tribromophenyl)-N'-aminooxamide,

N-(2-ethoxyphenyl)-N'-aminooxamide,

N-(2-methoxyphenyl)-N'-aminooxamide,

N-(2-ethylphenyl)-N'-aminooxamide,

N-(2-methylphenyl)-N'-aminooxamide,

N-(4-methoxycarbonylphenyl)-N'-aminooxamide,

N-(2-methoxycarbonylphenyl)-N'-aminooxamide,

N-(4-chlorophenyl)-N'-aminooxamide,

N-(4-bromophenyl)-N'-aminooxamide,

N-(4-methoxyphenyl)-N'-aminooxamide,

N-(2-octyloxyphenyl)-N'-aminooxamide,

N-(2-ethoxy-5-t-butylphenyl)-N'-aminooxamide,

N-(2-methoxy-3,5-di-t-butyl-6-methylphenyl)-N'-aminooxamide,

N-(2-methoxy-3-t-butyl-5-methyl)-N'-aminooxamide,

N-(2-methoxy-3,5-di-t-butylphenyl)-N'-aminooxamide,

N-(2-methoxy-5-t-butylphenyl)-N'-aminooxamide,

N-(2-ethoxyphenyl)-N'-(4-aminophenyl)oxamide,

N-(2-ethylphenyl)-N'-(3-aminophenyl)oxamide,

N-(2-ethoxyphenyl)-N'-(6-aminohexyl)oxamide, and

N-(2-methoxyphenyl)-N'-(2-aminoethyl)oxamide.

In general, any polymer or copolymer containing pendant cyclic anhydridegroups, either on the polymer backbone or grafted side chains, issuitable for attachment of the reactive stabilizers to form the polymerbound UV stabilizers of this invention. Due to cost and ease ofpreparation, the anhydride containing polymers are preferably polymersor copolymers of maleic anhydride.

To illustrate the broad nature of this invention, several types ofanhydride containing copolymers useful in this invention will bedescribed: (a) styrene-maleic anhydride copolymers, (b) alternatingcopolymers of maleic anhydride and alpha-olefins, (c) copolymers ofalkyl vinyl ethers and maleic anhydride, (d) maleic anhydride modifiedpolyolefins, (e) maleic anhydride adducts of hydrogenated polymers orcopolymers, (f) maleic anhydride adducts of EPDM, and (g) otheranhydride copolymers.

(a) Styrene-Maleic Anhydride Copolymers

These copolymers are a general class of compounds of alternatingcopolymers of styrene and maleic anhydride, or the non-equimolarcopolymers containing less than about 50 mole percent of the anhydridemonomer. The styrene may be replaced in whole or in part by othervinylaromatic monomers such as alpha-methylstyrene, nuclearmethylstyrenes, ethylstyrene, iso-propylstyrene, t-butylstyrene,chlorostyrenes, dichloro-styrenes, bromostyrenes, dibromostyrenes,vinylnaphthalene and the like. Similarly, the maleic anhydride can bereplaced in whole or in part by another alpha, beta-unsaturated cyclicdicarboxylic acid anhydride such as itaconic, aconitic, citraconic,mesaconic, chloromaleic, bromomaleic, dichloromaleic, dibromomaleic,phenylmaleic, and the like. The preferred alpha, beta-unsaturated cyclicanhydride is maleic anhydride. The copolymer may also contain atermonomer such as 1-3 carbons alkyl acrylate or methacrylate,acrylonitrile, methacrylonitrile, acrylamide, methacrylamide, acrylicacid or methacrylic acid.

Suitable copolymers may be prepared by any of the several methodsavailable for the preparation of styrene-maleic anhydride copolymers orthey may be purchased commercially. Non-equimolar copolymers may beprepared by solution polymerization directly from the respectivemonomers by the incremental addition of the reactive monomer as taughtby U.S. Pat. No. 2,971,939, by a continuous recycle polymerizationprocess such as described in U.S. Pat. Nos. 2,769,804 and 2,989,517, bythe suspension polymerization process described in U.S. Pat. No.3,509,110, or by numerous known variations.

Also suitable are the rubber-modified copolymers where 5 to 40 percentby weight of one of the known elastomers has been incorporated into thevinylaromatic-alpha, beta-unsaturated dicarboxylic acid anhydridecopolymer. The elastomers may be incorporated into the anhydridecopolymers by blending, mixing, or copolymerizing the monomers in thepresence of the rubber.

Suitable rubbers, or elastomers, include conjugated 1,3-diene rubbers,styrene-diene copolymer rubbers, acrylonitrile-diene copolymer rubbers,ethylene-propylene copolymer rubbers, ethylene-propylene-dieneterpolymer rubbers, acrylate-diene copolymer rubbers, and mixturesthereof.

Preferred rubbers or diene rubbers such as homopolymers of conjugateddienes such as butadiene, isoprene, chloroprene, and piperylene andcopolymers of such dienes with up to 50 mole percent of one or morecopolymerizable mono-ethylenically unsaturated monomers, such asstyrene, substituted styrenes, acrylonitrile, methacrylonitrile andisobutylene.

Preferably, the elastomers are incorporated into the monomer mixtureprior to polymerization using, for example, the method of U.S. Pat. No.4,097,551 of U.S. Pat. No. 4,486,570 in which a mixture of at least tworubbery additives are present during the polymerization.

Particularly suitable for use are the non-equimolar copolymers ofstyrene and maleic anhydride designated Dylark™ copolymers, commerciallyavailable from ARCO Chemical Company. Suitable Dylark™ copolymersinclude those of the 200 series and the 300 series and Dylark™ 600 and700. Those copolymers designated Dylark™ 250, Dylark™ 350 and Dylark™700 are impact modified and are especially useful.

The SMA™ resins are low molecular weight styrene-maleic anhydridecopolymers (MW 700-1900) and are also useful in this invention. The lowmolecular weight SMA resins SMA™ 1000, 2000 and 3000 are also useful inthis invention.

Also suitable are the styrene-maleic anhydride copolymers or rubbermodified styrene-maleic anhydride copolymers where a portion of themaleic anhydride groups are converted to maleimide groups orN-substituted maleimide groups. The partially imidated copolymers can beprepared by treating the SMA polymer with a primary amine in a postpolymerization step as described in U.S. Pat. No. 3,998,907 or duringthe polymerization as described in U.S. Pat. No. 4,381,373.

The molar ratio of the amine to the maleic anhydride in the copolymershould be less than 0.8 to allow attachment of the stabilizer groups.The formation of the maleimide groups that don't contain stabilizergroups may be formed before, during or after the formation of themaleimide groups containing stabilizer groups. Suitable amines for thispurpose are ammonia, primary alkyl amines and primary aryl amines. Longchain primary alkyl amines will beneficially aid in flow properties ofthe system while primary aryl amines will increase the thermal stabilityand heat distortion properties of the system. Aniline is the preferredaromatic amine for increasing the thermal stability of the polymersystem. Brominated or chlorinated primary amines will increase the fireretardancy of the system.

The SMA copolymer may optionally contain a termonomer such as a 1-3carbons alkyl acrylate or methacrylate, acrylonitrile,methacrylonitrile, acrylamide, methacrylamide, acrylic acid ormethacrylic acid. Rubber modified terpolymers of styrene, maleicanhydride and alkyl (1-3 carbons) methacrylates are described in U.S.Pat. No. 4,341,695. Incorporation of the methacrylate comonomer atspecific levels (2 to 20% by weight) increases the heat distortiontemperature of the polymer, raises the tensile strength and increasesthe gloss of the rubber-modified polymer. The polymer composition isconveniently prepared by dissolving the rubber in a solution of themonoalkenyl aromatic component and the methacrylate ester in a suitablesolvent and then polymerizing the solution with the anhydride componentin the manner described in, for example, U.S. Pat. Nos. 2,971,939,3,336,267 and 3,919,354.

The Cadon™ resins (Monsanto Chemical Company) are a commercial series ofstyrenemaleic anhydride polymer alloys with ABS. Rubber-modifiedversions are also available and are also suitable for this invention.

Also suitable are the rubber modified styrene maleic anhydride resinsdescribed in U.S. Pat. No. 4,522,983 where a minor amount of a nuclearsubstituted methylstyrene is included in the composition to increase theimpact strength of the composition.

The styrene-maleic anhydride polymers may be further modified bycopolymerizing the monomers in the presence of other monomers. Inaddition to the acrylates, methacrylates acrylonitrile andmethacrylonitrile previously mentioned, other suitable monomers includethe ethlenically unsaturated carboxylic acids, preferably acrylic andmethacrylic acids, acrylamide and methacrylates such asdimethylaminoalkyl (1-6 carbons) acrylate or methacrylate such asdimethylaminoethyl acrylate or methacrylate, and vinyl esters derivedfrom saturated carboxylic acids of 2 to 22 carbon atoms such as vinylacetate or vinyl propionate.

Further modification of the styrene-maleic anhydride copolymers can beaccomplished by carrying out the copolymerization in the presence ofcrosslinking monomers having two or more ethylenically unsaturateddouble bonds such as divinylbenzene, 1,4-butadiene, divinyl ether,ethylene glycol dimethacrylate, butanediol dimethacrylate, triallylcyanurate and similar type compounds. The crosslinking monomers areemployed in amounts of from 0.01 to 5, preferable from 0.1 to 2 molepercent based on maleic anhydride.

(b) Alternating Copolymers of Maleic Anhydride and Alpha-Olefins

These copolymers are exemplified by U.S. Pat. Nos. 3,553,177, 3,560,455,3,560,456 and 3,560,457. Each of these patents describes a copolymer ofmaleic anhydride with a specific alpha-olefin such as 12 to 30 carbonalpha-olefins. The copolymers of 6 to 10 carbon alpha-olefins aredisclosed in U.S. Pat. No. 3,488,311. Terpolymers of maleic anhydrideand at least one lower alpha-olefin and at least one higher alpha-olefinare also known, as shown by Canadian Patent 1,180,497. PA-18 is anexample of a commercially available alternating copolymer of maleicanhydride and octadecene-1.

Also suitable for this invention are the terpolymers disclosed in U.S.Pat. Nos. 4,522,922 and 3,723,375. These are basically terpolymers ofcyclic alpha, beta-unsaturated dicarboxylic acid anhydrides, aromaticmono-alkenyl monomers and higher 1-alkenes. Preferably, they areterpolymers of styrene, maleic anhydride and alpha-olefins having 10 ormore carbon atoms. Both pure alkenes and mixed alkenes can be utilizedin preparing the terpolymers.

(c) Copolymers of Alkyl Vinyl Ethers and Maleic Anhydride

These copolymers are readily prepared in bulk or solution using freeradical initiators (e.g., lauroyl peroxide) (British Patent 1,117,515).Low, medium, and high molecular weight grades are commerciallyavailable. Commercial grades include the Gantrez™ resins (GeneralAniline and Film). Suitable alkyl vinyl ethers for copolymerizationinclude methyl, ethyl, propyl, isopropyl, n-butyl, isobutyl, amyl,isoamyl, hexyl, heptyl, octyl, 2-ethyl hexyl, nonyl, decyl, dodecyl,hexadecyl, and octadecyl vinyl ethers.

(d) Maleic Anhydride Modified Polyolefins

These polymers have the following formula: ##STR10## where P--represents an olefin polymer residue which is based on a preponderanceof ethylene, propylene or 1-butene, and having a valence of p. It can beeither a high or low density polyethylene residue, a polypropyleneresidue or a residue of a copolymer of ethylene with 1-butene, a residueof a copolymer of ethylene and propylene, a residue of apropylene-butene copolymer or a residue of such a propylene copolymerwith an olefin having up to about six carbon atoms.

The maleic anhydride-modified polyolefins are materials containing about0.2 to 9% by weight of combined maleic anhydride, preferably about 2 to5%. One embodiment of these materials is a commercially availableproduct, sold under the trademark "Hercoprime™" by Hercules Inc.Polyethylene or polypropylene modified with maleic anhydride isavailable commercially under the trademark "Plexar™". Any polymer orcopolymer of ethylene, propylene, or 1-butene can be modified via themaleic anhydride moiety to form the substrate molecule, includingpolyethylene, polypropylene, ethylene-propylene copolymer,propylene-butene-1 copolymer, or butene-1-ethylene copolymer. The mostfrequently encountered and the preferred maleic anhydride modifiedpolyolefin is that based on polypropylene.

The preparation of maleic anhydride modified polypropylene is describedin U.S. Pat. No. 3,483,276. Briefly, the preparation consists ofexposing the olefin polymer to a material or condition which will inducethe formation of active, free radical sites thereon with which maleicanhydride can react. Active centers can be induced, e.g., by subjectingthe polymer to the action of high energy ionizing radiation such asgamma rays, X-rays, or high speed electrons, by contacting it, either asa solid or a solution in a solvent, with a free radical producingmaterial such as dibenzoyl peroxide, dilauroyl peroxide, dicumylperoxide or t-butyl perbenzoate, or by simply milling it in the presenceof air. The preferred method is the reaction of the polyolefin withmaleic anhydride in solvent solution in the presence of a free radicalinitiator.

The olefin polymer based maleimides of the invention are prepared bygraft modifying the appropriate polymer backbone with a maleic anhydrideand thereafter reacting said anhydride modified olefin polymer withstabilizers containing primary amino or hydrazide functional groups. Aless preferred method is to modify the appropriate polymer backbone withN-(stabilizer substituted)maleimides of formula: ##STR11## where R¹, R²and G are as previously defined.

The graft modification of EPDM by maleic anhydride in the presence ofdicumyl peroxide and benzoyl peroxide is described by DeVito andco-workers (G. DeVito, N. Lanzetta, G. Maglio, M. Malinconico, P. Musta,R. Palumbo, J. Polym. Sci., Polym. Chem, Ed., 22, pp 1335-47 (1984)).

(e) Maleic Anhydride Adducts of Hydrogenated Polymers or Copolymers

These are polymeric products containing pendant succinic anhydridegroups which are formed by reacting maleic anhydride with hydrogenatedpolymers of conjugated dienes or hydrogenated copolymers of conjugateddienes and vinyl aromatic hydrocarbons containing a residualunsaturation level of from 0.5 to 20 percent of their originalunsaturation level prior to hydrogenation. The reaction, which isconducted by heating a mixture of the maleic anhydride and hydrogenatedpolymer or copolymer containing residual unsaturation, proceeds by meansof a reaction mechanism referred to as an "ENE" type reaction. Themaleic anhydride adds to the unsaturation of the polymer to form thepolymer product containing the pendant succinic anhydride groups. Thispolymer, by virtue of the pendant anhydride groups, can be reacted withstabilizers containing primary amino or hydrazide groups to form thepolymer bound stabilizers of the invention.

The amounts of maleic anhydride employed in the reaction can varyconsiderably depending on the specific nature of the hydrogenatedpolymer and the properties desired in the final product. In general, theamount of maleic anhydride employed may range from 0.1 to about 25percent by weight based on total weight of maleic anhydride andhydrogenated polymer with a preferred amount being from 0.2 to 5 percentby weight.

Various polymers of conjugated dienes and copolymers of conjugateddienes and vinyl aromatic hydrocarbons may be hydrogenated for use inpreparing the maleic anhydride adduct component of the compositions ofthe invention. Polymers of conjugated dienes which may be hydrogenatedinclude polymers derived from one or more conjugated diene monomers.Thus, polymers derived from a single conjugated diene such as1,3-butadiene (i.e., a homopolymer) or polymers derived from two or moreconjugated dienes such as, for example, 1,3-butadiene and isoprene or1,3-butadiene and 1,3-pentadiene (i.e., a copolymer) and the like may beutilized. Copolymers which may be hydrogenated include random copolymersof conjugated dienes and vinyl aromatic hydrocarbons and blockcopolymers of conjugated dienes and vinyl aromatic hydrocarbons whichexhibit elastomeric properties.

(f) Maleic Anhydride Adducts of EPDM

These are prepared by the thermal addition of maleic anhydride toelastomeric copolymers of ethylene and propylene which have asubstancially saturated hydrocarbon backbone chain and unsaturatedhydrocarbon side-chains. The preparation of these adducts is describedin U.S. Pat. No. 3,884,882.

(g) Other Anhydride Copolymers

Examples of these copolymers are as follows:

1) vinyl acetate-maleic anhydride copolymer,

2) ethylene-vinyl acetate-maleic anhydride terpolymer,

3) isobutylene-maleic anhydride copolymer,

4) graft polyols containing styrene-maleic anhydride copolymer in thegrafted chain,

5) styrene-maleic anhydride-2,4,6-tribromophenyl acrylate terpolymer,

6) maleic anhydride-divinylbenzene-styrene terpolymer,

7) ethylene-maleic anhydride-styrene graft copolymer,

8) methyl methacrylate-maleic anhydride copolymers,

9) butyl methacrylate-maleic anhydride-styrene copolymers, and

10) ethylene-maleic anhydride copolymers.

Other suitable maleic anhydride copolymers include the terpolymers ofanhydrides, aromatic mono-alkenyl monomers and higher 1-alkenesdescribed in U.S. Pat. No. 4,522,992, the tribromophenylacrylate-epichlorohydrin-maleic anhydride-styrene copolymer described inU.S. Pat. No. 4,108,943, and the methyl methacrylate-maleicanhydride-styrene copolymers disclosed in Japanese Patents 59/221,314and 59/221,315 (CA102: 150317x and 150318y), divinyl ether-maleicanhydride copolymers from Adica Labs (Pivan), apolybutadiene-poly-styrene-maleic anhydride terpolymer referred to asRicon™ 184/MA, a product of Colorado Chemical Specialties, Inc., andethylene/vinyl acetate copolymer grafted with maleic anhydride such asModic E 310 K a product of Mitsubishi Chemical Industries Co.

In addition, poly(maleic anhydride) such as Belcene, a product ofCiba-Geigy, is also suitable in this invention.

Anhydride polymers containing glutaric anhydride units can also be usedin this invention. Such polymeric anhydrides are available from polymersand copolymers of acrylic and methacrylic acid by heating underdehydrating conditions, with or without a catalyst (European Patent76,691).

Synthesis

The polymer bound UV stabilizers of this invention can be prepared byadding the reactive UV stabilizer to the anhydride polymer or copolymerunder reactive conditions. It is within the scope of this invention toemploy mixtures of functionalized UV stabilizers. Whether a singlefunctionalized UV stabilizer or multiple functionalized UV stabilizersare used, the total equivalents of UV stabilizer should not exceed theequivalents of anhydride in the polymer or copolymer. Additionalreactive species can be attached to the polymers or copolymers. Toproperly adjust the stoichiometry of multiple reactive additives, therelative anhydride content of the polymer or copolymer substrate must beconsidered. It have been found that the least reactive stabilizers canbe advantageously added first and the more reactive ones later in thepreparation. Alternately, the stabilizers can be blended together andadded to the anhydride polymer or copolymer under reactive conditions.

The reaction of the reactive stabilizers with anhydride polymers orcopolymers may be carried out in inert solvents such as benzene,toluene, xylene, mesitylene, chlorobenzene, dimethylformamide,tetrahydrofuran and aliphatic hydrocarbons. In some cases the reactionmay stop at the intermediate amic acid or partial conversion of the amicacid to the imide may occur. The amic acids cyclize to the desiredimides at higher temperatures.

Preferably, the reactive stabilizers are attached to the anhydridepolymers or copolymers by a melt blending step in the absence of asolvent. This can be accomplished at a temperature above the softeningpoint of the anhydride polymer or copolymer using any conventional meltmixing apparatus such as a plastograph, Banbury mixer, two roll mill,single or twin screw extruder or any other method which appliessufficient heat (e.g., 175° to 275° C.) and shear to the ingredients toobtain a satisfactory blend. Preferably, the reaction should be carriedout in an inert atmosphere such as nitrogen.

The reaction may be carried out for times varying from 30 seconds to 48hours depending upon the degree of conversion of the anhydride to imidedesired, the reactivity of the reactive stabilizers, the reactiontemperature employed, the presence or absence of a solvent, and the useor non-use of a catalyst. The temperature range includes from 20° C. tothe decomposition temperature of either starting material. At lowerreaction temperatures, the reactive UV stabilizers become attached tothe polymers as amic acid derivatives. For solution reactions,temperatures are conveniently controlled by judicious choice of solventswithin an appropriate boiling range. Temperatures in this case rangefrom 20° C. to approximately 225° C., preferably from 75° C. to 200° C.and most preferably from 110° C. to 200° C. Reaction times for solventreaction range from several minutes to 40 hours. Higher reactiontemperatures will reduce time for conversion to the desired product(s).Preferably, solvent reaction times will be between 15 minutes and 8hours and most preferably between 15 minutes and 4 hours. In addition,azeotropic water removal from the solvent will facilitate most solventreactions.

Appropriate temperatures for melt processing the reactive components canrange from 20° C. to greater than 300° C. in the case of engineeringthermoplastics. Generally, the preferred range is from the softeningtemperature of the starting polymer to about 300° C. Most preferably,the temperature range will be from 150° C. to 300° C. The time requiredat the higher temperatures of melt processing are preferably from 30seconds to 8 hours and most preferably from 30 seconds to about 1 hour.

As reaction temperatures are increased, as in the case of engineeringthermoplastics, the amic acids initially formed tend to cyclize toimides. Imide formation in most cases is assured by temperaturesexceeding 225° C.

In addition, the polymer bound stabilizers can be prepared in thepresence of inert polymers such as HIPS, ABS, SAN, MBS, ASA,polystyrene, polyolefins, various copolymers of polystyrene and rubberymaterials, poly (phenyl oxide), poly(phenylene ether) and variouscombinations thereof. These stabilized polymer alloys or blends can beprepared in solution or in a melt blending step in any conventional meltmixing apparatus such as a Banbury mixer or an extruder. In addition,once the stabilizers are attached to the anhydride polymers orcopolymers, the modified anhydride polymer or copolymer (or modifiedanhydride polymer or copolymer blend) may be blended with polymers orcopolymers containing reactive carbonyl groups such as nylon,polycarbonate, polyesters and polyarylates.

It is within the scope of this invention that the anhydride polymers orcopolymers may be partically imidized with ammonia, primary alkyl oraromatic amines and the residual anhydride groups either totally orpartially reacted with the reactive stabilizers to form maleimidegroups. Likewise, the anhydride polymers or copolymers may be reactedwith the reactive stabilizer groups first and then the residualanhydride groups either totally or partially reacted with ammonia,primary alkyl or aromatic amines or the anhydride copolymers may bereacted simultaneously with the reactive stabilizers and the primaryamines. A particularly preferred embodiment is to partially imidize theanhydride copolymer with a 8-200 carbon primary alkyl amine or monoamine-terminated poly(oxyalkylene). Small amounts of amine-terminatedJeffamines (primary amine terminated block copolymers of ethylene oxideand propylene oxide, products of Texaco Chemical Company) willcontribute advantageous mold release properties to the polymers orcopolymers. These 8-200 carbons alkyl or poly(oxyalkylene) substituentswill also lower the Tg of the modified copolymers, increase theircompatibility with other polymeric compositions such as polyolefins,lower processing temperatures, increase melt flow and may alsocontribute to lubricating properties.

Residual carboxyl or anhydride groups may be reacted with aqueous basesor metallic oxides to form ammonium or metal salts along the polymer.Care must be taken to avoid saponification of the stabilizer groups.

It is also within the scope of this invention that the anhydridepolymers or copolymers may be partially imidized with otherfunctionalized amines or hydrazides which will add additional propertiesto the polymers or copolymers. For example, attachment oftrialkoxysilylalkylamines such as aminomethyltrimethoxysilane,3-aminopropyltriethoxysilane or 3-aminopropyltri(n-propyloxy)silane (seeU.S. Pat. No. 3,755,354). Alkoxysilane groups enhance the ability of thepolymer or copolymer system to accept fillers. Likewise, reaction ofchlorinated or brominated primary amines or hydrazides will contributeflame retardant properties to the polymers or copolymers. Antistaticproperties can be introduced in a similar manner. For example, theanhydride copolymers may be partially reacted with3-dimethylaminopropylamine to form the 3-dimethylaminopropylimide andthen in a subsequent step the dimethylaminopropyl group may bequaternized with an alkyl halide such as methyl iodide (see U.S. Pat.No. 3,555,001).

When the attachments are run in solution, the products can be isolatedby removal of the solvent or by precipitation of the product in anon-solvent such as methanol or hexane. In the latter case, the productis separated from the solvent, washed with fresh non-solvent and driedin an oven at elevated temperature, preferably under vacuum or an inertatmosphere.

When the attachments are carried out in a mixer in the molten state, theblended product is cooled, ground up in a grinder or pelletized anddried in an oven at elevated temperatures, preferably, under vacuum oran inert atmosphere. When the reaction is carried out in an extruder,the extrudate is cooled, either by an inert gas or by a cooling bath,dried if necessary, pelletized or ground up and, if necessary, redriedin an oven.

It is generally beneficial to attach stabilizing groups to the anhydridepolymers or copolymers which will provide synergistic stabilizingeffects. This would reduce the concentration requirements of the polymerbound additives thereby providing economic benefits.

The polymer bound stabilizers of this invention are useful as lightstabilizers for synthetic polymers which are normally subject to actiniclight degradation. Depending upon the mode of attachment, other benefitsmay be gained. When the attachment is accomplished by reacting theanhydride polymer or copolymer with a hydrazide functionalizedstabilizer, the resulting polymer may exhibit enhanced thermalstability.

Since the stabilizer groups are bound to polymers, they will not be lostfrom the polymer system by volatilization, migration or extraction evenat high temperatures. This makes these stabilized polymers especiallyattractive in food grade applications.

The polymer bound stabilizers of this invention can be used bythemselves as stabilized compositions or they may be blended with otherpolymers to form stabilized blends. When blending with other polymers itis advantageous to try to match the polymer backbone of the anhydridecontaining copolymer with the polymer or copolymer to be stabilized. Forexample, better results are obtained when stabilizing polypropylene, ifthe stabilizer groups are attached to an octadecene-maleic anhydridecopolymer rather than a styrene-maleic anhydride copolymer. Likewise,the styrene-maleic anhydride copolymers are more suitable for attachmentof the stabilizer groups when stabilizing styrenics.

Concentrates of the polymer bound stabilizers in other polymers can beused as masterbatches to stabilize other polymer systems. For example,masterbatches of modified Dylark™ resins in polystyrene may be blendedwith poly(phenylene oxide)-polystyrene blends to stabilize them againstphotochemical degradation. The amount of concentrate required willdepend on the stabilizer groups attached, their concentration in theconcentrate, additional additives present, the particular polymer systemto be stabilized, and the degree of stabilization desired.

In general it is advisable to have about 0.01 to 5% by weight of theactive stabilizer group (i.e., the UV stabilizer group) in the finalpolymer or copolymer blend. A preferred range is from about 0.05 toabout 2% by weight and a more preferred range is from about 0.05 toabout 1% by weight of each active stabilizer group.

At times it may be beneficial to add extraneous additives which will actas synergists with one or more of the polymer bound stabilizer groups.Some synergistic systems application to this invention would include thefollowing non-exclusive examples:

1) hindered amines and 2-(2-hydroxyphenyl)-2H-benzotriazoles

2) hindered amines and 2-hydroxybenzophenones

3) hindered phenols and 2-hydroxybenzophenones

In addition hindered amines, 2-hydroxybenzophenones,2-(2-hydroxyphenyl)-2H-benzotriazoles, and phenyl salicylates all wouldprovide synergistic effects with added phosphite stabilizers.

The polymer bound UV stabilizers of this invention can be used togetherwith other additives to further enhance the properties of the finishedpolymer. Examples of other additives that can be used in conjunctionwith the stabilizers of this invention include entioxidants such asalkylated monophenols, alkylated hydroquinones, hydroxylatedthiodiphenyl ethers, alkylidene-bis-phenols, hindered phenolic benzylcompounds, acylaminophenols, esters of3-(3,5-di-t-butyl-4-hydroxyphenyl)propionic acid, esters of3-(5-t-butyl-4-hydroxy-3-methylphenyl)propionic acid,3-)3,5-di-t-butyl-4-hydroxyphenyl)propionic acid amides; UV absorbersand light stabilizers such as 2-(2'-hydroxyphenyl)-2H-benzotriazoles,2-hydroxybenzophenones, benzylidene malonate esters, esters ofsubstituted or unsubstituted benzoic acids, diphenyl acrylates, nickelchelates, oxalic acid diamides, hindered amine light stabilizers; otheradditives such as metal deactivators, phosphites and phosphonites,peroxide decomposers, fillers and reinforcing agents, plasticizers,lubricants, corrosion and rust inhibitors, emulsifiers mold releaseagents, pigments, carbon black, fluorescent brightners, both organic andinorganic flame retardants and non-dripping agents, melt flow improversand antistatic agents. Numerous examples of suitable additives of theabove type are given in Canadian Patent 1,190,038.

If higher levels of a stabilizer are attached to the anhydride polymeror copolymer, it may be used as a stabilizer concentrate and may beblended with other polymers or copolymers.

Examples of polymers and copolymers which may be stabilized by thesepolymeric UV stabilizers include:

1. Polyolefins such as high, low and linear low density polyethylenes,which may be optionally crosslinked, polypropylene, polyisobutylene,poly(methylbutene-1), polyacetylene and in general polyolefins derivedfrom monomers having from two to about ten carbon atoms and mixturesthereof.

2. Polyolefins derived from diolefins such as polybutadiene andpolyisoprene.

3. Copolymers of mono or diolefins such as ethylene-propylene,propylene-butene-1 propylene-isobutylene and ethylene-butene-1copolymer.

4. Terpolymers of ethylene and propylene with dienes (EPDM) such asbutadiene, hexadiene, dicyclopentadiene and ethylidene norbornene.

5. Copolymers of alpha-olefins with acrylic acid or methacrylic acids ortheir derivatives such as ethylene-acrylic acid, ethylene-methacrylicacid and ethylene-ethyl acrylate copolymers.

6. Styrenic polymers such as polystyrene (PS) and poly(p-methylstyrene).

7. Styrenic copolymers and terpolymers such as styrene-butadiene (SBR),styrene-allyl alcohol and styrene-acrylonitrile (SAN),styrene-acrylonitrile (SAN), styrene-acrylonitrile-methacrylateterpolymer, styrene-butadiene-styrene block copolymers (SBS), rubbermodified styrenics such as styrene-acrylonitrile copolymers modifiedwith acrylic ester polymer (ASA), graft copolymers of styrene on rubberssuch as polybutadiene (HIPS), polyisoprene or styrene-butadiene-styreneblock copolymers (Stereon™ from Firestone Synthetic Rubber and LatexCo.), graft copolymers of styrene-acrylonitrile on rubbers such asbutadiene (ABS), polyisoprene or styrene-butadiene-styrene blockcopolymers, graft copolymers of styrene-methyl methacrylate on rubberssuch as polybutadiene (MBS), butadiene-styrene radial block copolymers,(e.g., KRO 3 of Phillips Petroleum Co.), selectively hydrogenatedbutadiene-styrene block copolymers (e.g. Kraton G from Shell ChemicalCo.) and mixtures thereof.

8. Polymers and copolymers derived from halogen-containing vinylmonomers such as poly(vinyl chloride), poly(vinyl fluoride),poly(vinylidene chloride), poly(vinylidene fluoride),poly(tetrafluoroethylene) (PTFE), vinyl chloride-vinyl acetatecopolymers, vinylidene chloride vinyl acetate copolymers, andethylene-tetrafluoroethylene copolymers.

9. Halogenated rubbers such as chlorinated and/or brominated butylrubbers or polyolefins and fluoroelastomers.

10. Polymers and copolymers derived from alpha, beta-unsaturated acids,anhydrides, ester, amides and nitriles or combinations thereof such aspolymers and copolymers of acrylic and methacrylic acids, alkyl and/orglycidyl acrylates and methacrylates, acrylamide and methacrylamide,acrylonitrile, maleic anhydride, maleimide, the various anhydridecontaining polymers and copolymers described in this disclosure,copolymers of the above polymers and various blends and mixtures thereofas well as rubber modified versions of the above polymers andcopolymers.

11. Polymers and copolymers derived from unsaturated alcohols or theiracylated derivatives such as poly(vinyl alcohol), poly(vinyl acetate),poly(vinyl stearate), poly(vinyl benzoate), polu(vinyl maleat),poly(vinyl butyral), poly(alyl phthalate), poly(allyl diethylene glycolcarbonate) (ADC), ehtylene-vinyl acetate copolymer and ethylene-vinylalcohol copolymers.

12. Polymers and copolymers derived from unsaturated amines such aspoly(allyl melamine).

13. Polymers and copolymers derived from epoxides such as polyethleneoxide, polypropylene oxide and copolymers thereof as well as polymersderived from bis-glycidyl ethers.

14. Poly(phenylene oxides), poly(phenylene ethers) and modificationsthereof containing grafted polystyrene or rubbers as well as theirvarious blends with polystyrene, rubber modified polystyrenes or nylon.

15. Polycarbonates and especially the aromatic polycarbonates such asthose derived from phosgene and bisphenols such as bisphenol-A,tetrabromobisphenol-A and tetramethylbisphenol-A.

16. Polyester derived from dicarboxylic acids and diols and/orhydroxycarboxylic acids or their corresponding lactones such aspolyalkylene phthalates (e.g., polyethylene terephthalate (PET),polybutylene terephthalate (PBT), and poly(1,4-dimethylcyclohexaneterephthalate) or copolymers thereof and polylactones such aspolycaprolactone.

17. Polyarylates derived from bisphenols (e.g., bisphenol-A) and variousaromatic acids such as isophthalic and terephthalic acids or mixturesthereof.

18. Aromatic copolyestercarbonates having carbonate as well as esterlinkages present in the backbone of the polymers such as those derivedfrom bisphenols, iso- and terephthaloyl chlorides and phosgene.

19. Polyurethanes and polyureas.

20. Polyacetals such as polyoxymethylenes and polyoxymethylenes whichcontain ethylene oxide as a comonomer.

21. Polysulfones, polyethersulfones and polyimidesulfones.

22. Polyamides and copolyamides which are derived from diamines anddicarboxylic acids and/or from aminocarboxylic acids or thecorresponding lactones such as the following nylons: 6, 6/6, 6/10, 11and 12.

23. Polyimides, polyetherimides, polyamideimides and copolyetheresters.

24. Cross-linked polymers which are derived from aldehydes on the onehand and from phenols, ureas and melamine on the other hand such asphenol-formaldehyde, urea-formaldehyde and melemine-formaldehyde resins.

25. Alkyl resins such as glycerol-phthalic acid resins and mixturesthereof with melamine-formaldehyde resins.

26. Unsaturated polyester resins which are derived from copolyesters ofsaturated and unsaturated dicarboxylic acids with polyhydric alcohols aswell as from vinyl compounds (crosslinking agents) and alsohalogen-containing, flame resistant modifications thereof.

27. Natural polymers such as cellulose, natural rubber as well as thechemically modified homologous derivatives thereof such as celluloseacetates, cellulose ethers such as methyl and ethyl cellulose.

In addition, the polymer bound stabilizers of this invention may be usedto stabilize various combinations or blends of the above polymers orcopolymers. They are particularly useful in the stabilization ofpolyolefins, acrylic coatings, styrenics, rubber modified styrenicspoly(phenylene oxides) and their various blends with styrenics,rubber-modified styrenics or nylon.

EXAMPLES

The following reactive additives were used in the preparation of thepolymer bound stabilizers of the examples:

A. (4-benzoyl-3-hydroxyphenoxy)acetylhydrazide (MW=285)

B. (4-(2H-benzotriazol-2-yl)-3-hydroxyphenoxy)acetyl hydrazide (MW=300)

C. N-(3-hydroxy-4-(phenoxycarbonyl)phenyl N'-aminooxamide (MW=315)

D. Jeffamine™ M-360

E. Zinc Oxide

Reactive stabilizer A was prepared by the hydrazinolysis of thecorresponding methyl or ethyl ester. Reactive additive C was preparedfrom phenyl 4-aminosalicylate in a two step procedure: (1) reaction ofthe amine with ethyl oxalyl chloride and (2) hydrazinolysis of theamide-ester thus formed.

The following maleic anhydride copolymers were used in the preparationof the polymer bound stabilizers of the examples.

SMA™ 1000 is a low molecular weight alternating copolymer of styrene andmaleic anhydride with number average molecular weight of approximately1600.

SMA™ 2000 is a low molecular weight copolymer of styrene and maleicanhydride containing approximately 2 styrene units for each maleicanhydride unit and has a number average molecular weight ofapproximately 1700.

SMA™ 3000 is a low molecular weight copolymer of styrene and maleicanhydride containing approximately 3 styrene units for each maleicanhydride unit and has a number average molecular weight ofapproximately 1900. These SMA resins are products of the Arco ChemicalCompany, Division of Atlantic Richfield Company.

EMA-1103 is an alternating ethylene-maleic anhydride copolymer and wasobtained from the Monsanto Chemical Co.

Cadon™ resins are a commercial series of styrene-maleic anhydridepolymer alloys with ABS and were obtained from the Monsanto Chemical Co.

PA-18 is a copolymer of 1-octadecene and maleic anhydride and wasobtained from Chevron Chemical Co. It has a molecular weight of about50,000.

Gantrez™ AN 119 is a methyl vinyl ether-maleic anhydride copolymercommercially available from GAF.

The Dylark™ resins are high molecular weight non-equimolar copolymers ofstyrene and maleic anhydride commercially available from Arco ChemicalCompany. Dylark™ 240 and 250 are rubber modified while Dylark™ 232 isnot. Dylark™ 150 is prepared by polymerizing about 92% by weight styrenemonomer and about 8% by weight maleic anhydride, in the presence ofabout 18 parts by weight Stereon™ Rubber 720 (Firestone Synthetic Rubberand Latex Co.) per 100 parts of combined styrene and maleic anhydride.

Ricon™ 184/MA is a polybutadiene-polystyrenemaleic anhydride terpolymerand is a product of Colorado Chemical Specialties, Inc.

The HIPS used was Dow Styron™ 489W.

EXAMPLE 1 Preparation of[4-(2H-benzotriazol-2-yl)-3-hydroxyphenoxy]acetyl hydrazide (CompoundB) 1. Preparation of ethyl[4-(2H-benzotriazol-2-yl)-3-hydroxyphenoxy]acetate

Into a 500 ml flask equipped with a reflux condenser were combined2-(2,4-dihydroxyphenyl)-2H-benzotriazole (15.8 g, 0.07 mole, preparedaccording to the procedure of Li et al, Monatsh, Chem., 115, 853-868(1984)), ethyl chloroacetate (8.6 g, 0.07 mole), potassium carbonate (15g), potassium iodide (0.5 g) and 250 ml acetone. The reaction mixturewas refluxed for 30 hours, cooled and poured into a beaker containing1.5 liters of water. The solution was acidifed with concentratedhydrochloric acid and the solid precipitate collected on a buchnerfunnel. The solid was recrystallized from ethanol yielding 8.1 g ofgray-purple crystals (mp 115°-117° C.). This material was recrystallizeda second time from ethanol yielding 7 g of gray-purple crystals (mp118°-120° C.). Liquid chromatographic analysis of this material showedit to consist of a singular component. The infrared spectrum of thismaterial showed the ester carbonyl at 1750 cm⁻¹. The UV absorptionspectrum of this material gave λmax(THF)=342, molar absorptivity=23000.

2. Preparation of Compound B

Into a 125 ml flask equipped with a magnetic stirrer were combined, theester prepared above (3.1 g, 0.01 mole), 30 ml of isopropanol, and 6 mlof 54% hydrazine (aqueous). This mixture was allowed to stir at ambienttemperature for 5 hours, and then was poured into a beaker containing400 ml water and 17.9 g of acetic acid. The mixture was stirred for 5minutes (pH=5). The solid product was isolated on a Buchner funnel andwashed with additional water. The solid was transferred to anotherbeaker and slurried with 5% sodium bicarbonate (stirred for 1 hour) thenisolated again and air dried on the funnel yielding 2.7 g of pinkcrystals. The infrared spectrum of this material showed the hydrazidecarbonyl at 1680 cm⁻¹. The UV absorption spectrum of this material gaveλmax(THF)=342, molar absorptivity=26000. Elemental analysis: theoretical% C=56.19%, % H=4.38%, % N=23.40%, %0= 16/04%; found % C=55.56%, %H=4.60%, % N=22.53%, %0=17.92%.

EXAMPLE 2 Attachment by Melt Blending of Compound A into Rubber ModifiedStyrene/Maleic Anhydride Copolymer and HIPS

Into the 200° C. mixing compartment of a Brabender Prep Center Mixerkept under a nitrogen atmosphere were placed 50 g of Dylark™ 250 and 150g of Styron™ 489W. This blend was mixed for 5 minutes at 20 RPM to allowformation of a uniform blend. At this time, 11.45 g (0.04 mole) ofCompound A were added over a 3 minute period with the mixer operating at60 RPM. The temperature rose to 214° C. and the mixing rate was loweredto 40 RPM. The blend was mixed under these conditions for 7 minuteswhile the temperature dropped to 208° C. The product was removed hot andcooled in a water bath, then dried in an oven at 60° C. The polymerblend was ground up in a grinder and redried. An infrared spectrum ofthe polymer taken in chloroform solution indicated that the anhydridehad been converted to imide having a strong carbonyl absorption at 1740cm⁻¹. Part of the polymer was dissolved in chloroform and precipitatedin methanol to give a light yellow product. An infrared spectrumindicated the presence of UV stabilizer in the precipitated polymer.

EXAMPLE 3 Attachment by Melt Blending of A into Styrene/Maleic AnhydrideCopolymer and Polystyrene

Into the 200° C. mixing compartment of a Brabender Prep Center Mixerkept under a nitrogen atmosphere were placed 50 g of Dylark™ 232 and 150g of Polystyrene. This blend was mixed for 5 minutes at 20 RPM to allowformation of a uniform blend. At this time, 13.2 g (0.048 mole) ofCompound A were added over a 3-4 minute period. The blend was mixedunder these conditions for 5-6 minutes. The product was removed hot andcooled in a water bath, then dried in an oven for 2 hours at 80° C. Thepolymer blend was ground up in a grinder. An infrared spectrum of thepolymer taken in chloroform solution indicated that the anhydride hasbeen converted to imide having a strong carbonyl absorption at 1735 cm⁻¹and weak residual anhydride absorption at 1780 cm⁻¹. The polymer wasdissolved in 100 ml of refluxing chloroform and precipitated in 800 mlof methanol. The precipitate was slurried with additional methanol andfiltered again to give a very light, almost white polymer. An infraredspectrum indicated that presence of the UV stabilizer in theprecipitated polymer. Thermal analysis of this polymer indicated twoglass transition temperatures (Tg) of 131° and 106° C.

EXAMPLE 4 Reaction of Various Styrene/Maleic Anhydride Copolymers with Ain Solution

Into a 500 ml round bottom flask equipped with a Dean-Stark trap andcondenser were placed 25 g of Dylark™ 232, 8.3 g (0.028 mole) ofCompound A, and 200 ml of xylene. This mixture was heated to boiling andrefluxed for 2 hours with azetropic removal of water as it formed. Thesolvent was stripped and the solid polymer was dissolved in 500 ml ofchloroform; then it was precipitated in 4 liters of methanol. Thepolymer was collected by filtration and further dried under high vacuum.The product was a white solid weighing 27.3 g and having a Tg of 119° C.The infrared spectrum of the polymer showed an imide carbonyl band at1720 cm⁻¹ and a residual anhydride carbonyl band at 1770 cm⁻¹.

Alternately, the following maleic anhydride copolymers were used withsimilar results:

Cadon™ 127 (7.0 g) and A (3.0 g) gave 10 g of white polymer with twoTg's of 104° C. and 144° C., compared to 130° C. for unmodified Cadon™127. The infrared spectrum of the polymer showed an imide carbonyl bandat 1735 cm⁻¹.

Gantrez™ AN-169 (3.7 g) and A (6.9 g) gave 9.3 g of slightly yellowpolymer with Tg of 162° C., compared to 158° C. for unmodified Gantrez™AN-169.

PA-18 Resin (5.6 g) and A (4.6 g) gave 9 g of yellow polymer with Tg of106° C., compared to 90° C. for unmodified PA-18. The infrared spectrumof the polymer showed an imide carbonyl band at 1720 cm⁻¹ and a residualanhydride carbonyl band at 1770 cm⁻¹.

EMA-103 (15 g) and A (6.9 g) gave 21 g of slightly yellow polymer withTg of 149° C., compared to 136° C. for unmodified EMA-103. The infraredspectrum of the polymer showed an imide carbonyl band at 1720 cm⁻¹ and aresidual anhydride carbonyl band at 1780 cm⁻¹.

EXAMPLE 5 Attachment of Compound A to Ricon™ 184MA Resin

Into a 500 ml round bottom flask equipped with a Dean-Stark trap andcondenser were placed 19.8 g of Ricon™ 184MA and 200 ml of xylene. Thismixture was heated to boiling and refluxed for 1 hour to dry thepolymer. The solution was cooled slightly and 2.9 g (0.01 mole) ofCompound A were added. The reaction mixture was refluxed for anotherhour with water removal. The solvent was stripped using an aspirator andhigh vacuum systems (vessel warmed with steam). The product was a veryviscous brown liquid weighing 24.5 g. An infrared spectrum of thispolymer showed the imide carbonyl band at 1735 cm⁻¹ and residualanhydride carbonyl band at 1785 cm⁻¹. Analysis of this polymer by liquidchromatography using an UV detector (254 nm) clearly showed that thepolymeric material had enhanced UV absorbance over unmodified Ricon™184MA. This further verifies the attachment of the UV absorber to thepolymer.

EXAMPLE 6 Attachment of Compound B to Styrene/Maleic Anhydride Copolymer

Into a 250 ml flask equipped with a stirrer, nitrogen atmosphere, andDear Stark trap, were combined 11.0 g of Dylark™ 150 and 100 of xylene.This was heated to reflux for 30 minutes to dry the polymer. To this wasadded Compound B (2.0 g) and refluxing with removal of water wascontinued for 3 hours. The xylene was stripped under reduced pressure(aspirator and high vacuum systems). The polymer residue was taken up in500 ml tetrahydrofuran and filtered to remove unreacted hydrazide. Afterfiltration the amount of solvent was reduced to about 200 ml and theproduct precipitated by addition of this solution to 1200 ml of hexane.The polymer product was isolated by filtration and dried for 3 days in avacuum oven yielding 9.8 g of light tan solid. The Tg of the polymer was128° C., compared to 120° C. for unmodified Dylark™ 150. The infraredspectrum showed the imide carbonyl at 1737 cm⁻¹ and residual anhydrideat 1782 cm⁻¹.

EXAMPLE 7 Attachment of Compound C to Styrene/Maleic Anhydride Copolymer

Into a 500 ml round bottom flask equipped with a Dean-Stark trap,condenser, nitrogen atmosphere, and mechanical stirrer were placed 15 gSMA™ 2000 and 200 ml of xylene. The resulting solution was refluxed withazeotropic removal of water for 30 minutes to dry the polymer. Thesolution was cooled slightly and 9.2 g (0.03 mole) of Compound C wasadded. The mixture was refluxed for 1 hour with removal of water asformed. The mixture was cooled and the polymer precipitate collected byfiltration. The product was ground up in a blender with hexane andfiltered again. The resulting white solid was dried under high vacuumyielding 18.3 g of material. The infrared spectrum of this polymershowed the imide carbonyl band at 1720 cm⁻¹, a residual anhydridecarbonyl band at 1780 cm⁻¹, a broad carbonyl band for the oxalicdicarbonyls and the aromatic ester at about 1680 cm⁻¹. This materialmelted at 280°-300° C.

EXAMPLE 8 Attachment of Compound A to Styrene/Maleic Anhydride Copolymer

Into mixing chamber of a Brabender Prep Center Mixer were placed 30.0 gof SMA™ 1000 and 0.075 g of Irganox™ 1076. The mixture was kept under anitrogen blanket while mixing at 40-50 RPM. Compound A (37.0 g, 0.13mole) was added over a 5 minute period. Mixing was continued anadditional 15 minutes to assure a complete reaction. The product masswas ground to a pale yellow powder in a mortar and with a pestle.Infrared analysis of this material confirmed the attachment of the UVabsorber. Analysis for residual Compound A showed it to be present tothe extent of 0.1%. The UV spectrum of the polymer showed twoabsorbances due to the attached UV absorber of λmax 286, E(1%, THF, 1cm)=290; λmax 327, E(1% THF, 1 cm)=180. The Tg of the polymer was 155°C. By differential scanning calorimetry the polymer was heated at 10° C.per minute without decomposition up to 300° C.

EXAMPLE 9 Attachment of Compounds A and D to Styrene/Maleic AnhydrideCopolymer

Into a 500 ml flask equipped with a stirrer, nitrogen atmosphere, andDean Stark trap, were combined 15.0 g SMA™ 1000 and 200 ml of xylene.This was heated to reflux in an attempt to dry the polymer. An insolublelump formed. To this was added Compound D (10.8 g) which softened thelump and began immediate water removal as the azeotrope. Refluxing withremoval of water was continued for an hour. The reaction mixture wascooled slightly and Compound A (8.6 g, 0.03 mole) was added. The mixturewas brought to reflux and heating continued for 1 hour. The xylene wasstripped under reduced pressure (aspirator and high vacuum systems) toyield 33.7 g of yellow solid. The UV spectrum of the polymer showed twoabsorbances due to the attached UV absorber at λmax 282, E(1%, THF, 1cm)=150; λmax 323, E(1%, THF, 1 cm)=74. The Tg of the polymer was 78.5°C. By differential scanning calorimetry, the polymer was heated at 10°C. per minute without decomposition up to 250° C. The infrared spectrumshowed the imide carbonyl at 1740 cm⁻¹ and residual anhydride at 1780cm⁻¹.

EXAMPLE 10 Attachment of Compound A to Styrene/Maleic AnhydrideCopolymer with Compound E

Into the 200° C. mixing chamber of a Brabender Prep Center Mixer wereplaced 220.0 g of Cadon™ 127 and 2.2 g of zinc oxide. The mixture wasblended for 5 minutes. Compound A (35.8 g, 0.12 mole) was added andmixing was continued an additional 5 minutes. The product mass wasremoved from the mixer, cooled, and ground to pale yellow chips.Infrared analysis of this material showed an imide carbonyl band at 1720cm⁻¹ and a residual anhydride carbonyl band at 1780 cm⁻¹. The Tg of thismaterial was determined to be 127° C., compared to 130° C. forunmodified Cadon™ 127.

EXAMPLE 11 Accelerated Weathering of HIPS Stabilized with Compound AAttached to SMA™ 1000 A. Preparation of Compound A/SMA 1000 Masterbatch

Into the 190° C. mixing chamber of a Brabender Plastograph were placed30.0 g of SMA™ 1000 and 0.075 g of Irganox™ 1076. The mixture wasblended for 5 minutes at 40 RPM. Compound A (39.0 g) was added over a 5minute period and mixing was continued an additional 10 minutes. Theproduct mass was removed from the mixer, cooled and ground to paleyellow powder.

B. Preparation of Test Samples

FORMULATION 1: Into the 200° C. mixing chamber of a Brabender PrepCenter Mixer was placed 250.0 g HIPS which was allowed to melt over aperiod of 5 minutes. To this was added 2.1 g of the stabilizermasterbatch prepared above. The mixture was blended an additional 10minutes. The product mass was removed from the mixer, cooled and groundto pale yellow granules. This procedure was repeated five more times toprepare sufficient material for molding.

FORMULATION 2: By a similar procedure, a test composition was preparedin which the stabilizer (Compound A) was attached to the SMA™ 1000 atthe same time as both of these were being blended with the HIPS. Forthis composition, 249 g of HIPS, 1.0 g of SMA™ 1000, 1.25 g of CompoundA, and 0.003 g of Irganox™ 1076 were used.

FORMULATION 3: As a control, the same procedure was used to blend 249 gof HIPS and 1.25 g of Uvinul™ 408 (2-hydroxy-4-octoxybenzophenone). Eachof these formulations contain 0.5% of a UV stabilizer. These threestabilized HIPS blends were injection molded into tensile bars using aNewbury 25 ton injection molder.

C. Accelerated Weathering

The tensile bars prepared above were weathered in a QUV AcceleratedWeathering Instrument. The instrument was equipped with FS-40 bulbs, andthe weathering cycle consisted of 8 hours light exposure at 60° C. and 4hours condensation in the dark at 50° C. Samples were removed aftercertain time periods and changes in polymer properties were determined.The results are recorded in Table I. These results clearly demonstratethe advantage of this invention.

                  TABLE 1                                                         ______________________________________                                        ACCELERATED WEATHERING TEST RESULTS                                           PROPERTY &  QUV EXPOSURE, HOURS                                               FORMULATION 100     270    570   700  770   1000                              ______________________________________                                        IZOD IMPACT                                                                   RETAINED, %                                                                   1           86      75     75    82         71                                2                                     67                                      3           83      72     66    59         59                                YID CHANGE*                                                                   1           17      31     38    41         40                                2                                     37                                      3           19      36     45    46         56                                TOTAL COLOR                                                                   CHANGE**                                                                      1            9      15     18    20         20                                2                                     18                                      3            9      17     21    21         26                                ______________________________________                                         *Yellowness Index change according to ASTM D1925                              **Total color according to CIE lab 1976 color scale L*A*B*               

What is claimed:
 1. A process for preparing a polymer bound ultravioletlight stabilizer by reacting an anhydride containing polymer orcopolymer having recurring units ##STR12## or both, in which the unitsoccur in the polymer backbone, on grafted side chains, as pendant unitsor as combinations thereof, where R¹ and R² are independently hydrogen,alkyl of 1-6 carbons, cycloalkyl of 5-7 carbons, phenyl, chlorine orbromine and x is 0 or 1, with 0.001 mole percent up to the molarequivalent of available anhydride present in the anhydride containingpolymer or copolymer of an ultraviolet light stabilizer of group (a)primary amino or hydrazido substituted 2-hydroxybenzophenones, (b)primary amino or hydrazido substituted2-(2-hydroxyphenyl)-2H-benzotriazoles, (c) primary amino or hydrazidosubstituted salicylate esters or (d) primary amino or hydrazidosubstituted oxalic acid amides, with the proviso that multiplecombinations of ultraviolet light stabilizers within the same group ofgroups (a)-(d) are permitted, at a temperature between 20° and 300° C.for between 30 seconds and 48 hours, wherein the reaction optionallyoccurs in the presence of an inert solvent.
 2. The process of claim 1 inwhich the ultraviolet light stabilizer is a primary amino2-(2-hydroxyphenyl)-2H-benzotriazole having a formula: ##STR13## whereinR⁶ is hydrogen, alkyl of 1-4 carbons, alkoxy of 1-4 carbons,alkoxycarbonyl of 2-11 carbons, carboxylic acid amide, chlorine,bromine, sulfonic acid or alkylsulfonyl, y is 1, 2 or 3, and rings A andB are optionally independently substituted with alkyl of 1-4 carbons,alkoxy of 1-4 carbons, chlorine or bromine.
 3. The process of claim 2wherein the functionalized ultraviolet light stabilizer is2-(2-hydroxy-3-aminomethyl-5-methylphenyl)-2H-benzotriazole.
 4. Theprocess of claim 1 in which the functionalized ultraviolet lightstabilizer is ##STR14## wherein R⁶ is hydrogen, alkyl of 1-4 carbons,alkoxy of 1-4 carbons, carboxyl, alkoxycarbonyl of 2-11 carbons,carboxylic acid amide, chlorine, bromine, sulfonic acid oralkylsulfonyl, and rings A and B are optionally independentlysubstituted with alkyl of 1-4 carbons, alkoxy of 1-4 carbons, chlorineor bromine.
 5. The process of claim 4 wherein the functionalizedultraviolet light stabilizer is3-(3-(2H-benzotriazol-2-yl)-4-hydroxy-5-t-butylphenyl)propionhydrazide.6. The process of claim 1 wherein the reaction is carried out in theabsence of solvent, and either by blending the stabilizer and polymersimultaneously or by adding the stabilizers sequentially or as a mixtureto molten polymer, and reacting for 30 seconds to 8 hours.
 7. Theprocess of claim 6 wherein the reaction is carried out in a meltblending apparatus selected from an extruder, a kneader, a roll mill, aBanbury mixer or a plastograph at temperatures of 150°-300° C. for 30seconds to 1 hour.
 8. The process of claim 1 wherein the reaction iscarried out in the presence of an inert solvent, at a temperature fromabout 25° C. to the boiling point of the solvent, for 15 minutes to 12hours, with optional removal of water as it is formed.
 9. The process ofclaim 8 wherein the inert solvent is selected from aromatichydrocarbons, chlorinated aromatic hydrocarbons, dimethylformamide,tetrahydrofuran or blends thereof.
 10. The process of claim 9 where thesolvent is selected from toluene, xylene, chlorobenzene or mesitylene.